RGB Colorimetric Method for the Quantitative Analysis of Levocetirizine Tablets

Abstract

This study presented a simple and not time-consuming method coupled with a RGB colorimetric technique using the built-in function of mobile phone digital imaging devices for quantitative analysis. The method was based on the detection of color intensities and the evaluation of relationship between measured color and concentration of sample. Materials and methods: The proposed method was applied successfully to analyze levocetirizine (LCTZ) quantitatively in pharmaceutical tablet dosage forms using bromocresol green (BCG) as a coloring agent. Bromocresol green solution only is a blue color. When it reacted with levocetirizine it formed a yellow-green complex.  The intensity of yellow-green complex color was depending on the concentration of drug sample. The complex solutions were transferred into standard glass cuvettes and then the images were recorded by mobile phone. The pixel array reader program was applied to evaluate the red-green-blue intensities (RGB scale) of the recorded images that were converted to the concentration which was calculated from the relationship of linear equation. Under the optimized condition, a calibration curve was established by the RGB scale and concentration of drug standard. Validation procedure was achieved concerning linearity, accuracy, and precision of developing method. Results: The proposed method obeyed Beer’s law and show linear relationship in concentration range of 2 - 40 µg mL^-1 of levocetirizine with a good coefficient of determination (r² = 0.9996). The limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.64 and 4.96 µg mL^-1, respectively. The common excipients used as additives in the pharmaceutical dosage form had shown no effect on the proposed method. The results acquired by the proposed method were compared favorably with those acquired by the reference method at a 95% confidence level with no significant difference (n=6). Conclusion: The developed method had shown accurate, precise, and reproducible. Moreover, this demonstrates the possibility of RGB colorimetric technique in the quantitative analysis of drugs in their pharmaceutical dosage forms with a simple procedure, low cost, and more applications for pharmaceutical analysis are expected to be use as an alternative method.